package thread;

import java.util.ArrayList;

public class Test {
    public static void main(String[] args) throws InterruptedException {
        ArrayList<Integer> list = new ArrayList<>();
        Thread t1 = new Thread(){
            public void run(){
                synchronized (list) {
                    for (int i = 0; i < 1000; i++) {
                        list.add(i);
                    }
                }
            }
        };
        Thread t2 = new Thread(){
            public void run(){
                synchronized (list) {
                    for (int i = 0; i < 1000; i++) {
                        list.add(i);
                    }
                }
            }
        };
        t1.start();
        t2.start();

        Thread.sleep(1000);//阻塞主线程的目的是等待上述两个线程执行完毕
        System.out.println(list.size());
    }
}
